Bring a large pot of salted water to a boil, add greens and bell peppers, and cook until bright and still crisp, about 3 minutes.
Use a slotted spoon to transfer the green beans and pepper to a large bowl filled with ice water. When cool, drain and move to a paper towel-lined baking sheet; pat dry.
In a small saucepan over medium heat, combine 2 cups water, vinegar, mushrooms and 1 teaspoon salt, stirring to dissolve the salt; cover and cook for 15 minutes. Remove pan from heat and let rest, covered, for another 15 minutes.
Drain mushrooms well and add them to a large bowl, along with the green beans, peppers and dressing. Toss and serve with fried onions sprinkled over the top.
For safe meat preparation, reference the USDA website.
For dips, make and enjoy your dip creation. Then, refrigerate within 2 hours or discard.